The invention relates to apparatus and methods for optically imaging features on a surface of a hand, such as fingerprints and palmprints.
Fingerprints and palmprints are commonly taken by applying ink to the surface of the skin and then transferring the ink to a paper medium for recording. The application of ink to the skin and the subsequent transfer to paper requires a skilled expert to produce high quality images. Optical systems for scanning fingerprint and palmprint images have been developed to avoid problems associated with ink-based methods. In common optical systems, a hand to be scanned is held against a transparent platen, and an optical detector scans light reflecting from the interface between the hand and the platen to generate signals representative of fingerprint or palmprint images. These signals are digitized, stored in digital computer memory, and processed for transmission or printing.